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Enhancement in boiling heat transfer performance using reduced graphene oxide coating with controllable components and porous structures

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Science China(Technological Sciences) 2023年第7期66卷 2080-2092页

作者： XU ZhiMing WANG XiaoLiang JIANG HongPeng ZHANG ZhiRong SHAN DeBin GUO Bin QIU YunFeng XU Jie Key Laboratory of Micro-Systems and Micro-Structures Manufacturing of Ministry of Education Harbin Institute of TechnologyHarbin 150080China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Medicine and Health Harbin Institute of TechnologyHarbin 150080China School of Chemistry and Chemical Engineering Yancheng Institute of TechnologyYancheng 224051China

Enhancement in boiling heat transfer performance is significant for addressing thermal management bottlenecks of advanced electronic *** graphene oxides(rGO)are regarded as promising candidates for thermal management due to their excellent thermal properties,chemical stability and adjustable *** this study,rGO coatings with micron pores and controllable oxygen contents are prepared on Al substrate via cathodic electrophoretic deposition and subsequent thermal annealing,leading to enhanced pool boiling *** heat transfer coefficient for Al/rGO450is 37.2 kW m-2K-1,which is increased by 112.6%compared with bare Al,also outperformed previously reported Al based *** is assumed that the hydrophilic and aerophobic r GO coatings effectively promote the liquid infiltration and bubble departure during pool boiling ***,repeatability tests indicate the durable stability of vertically oriented rGO *** nonequilibrium molecular dynamics simulation indicates that the interfacial transmission coefficients of Al/rGO increase after thermal annealing,indicative of the enhanced heat transfer performance of heterogeneous *** study opens a new avenue for endowing metal substrates with high pool boiling performance using porous carbon coating nanoengineering strategy with controllable morphology and components.

关键词： graphene cathodic electrophoretic deposition boiling heat transfer thermal reduction interfacial nanoengineering

Visualization of boiling heat transfer on Copper Surface with Different Wettability

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Journal of Thermal Science 2022年第6期31卷 1903-1913页

作者： LIU Dong LI Yunheng HU Anjie School of Civil Engineering and Architecture Southwest University of Science and TechnologyMianyang 621010China

In this work, a pool boiling visualization experiment platform was built to study the influence of wettability on the nucleate boiling heat transfer. The copper surface was prepared by chemical etching method, and three types of copper surfaces(hydrophilic, hydrophobic, and smooth) were obtained. The boiling heat transfer characteristics of these three surfaces were discussed based on the obtained heat transfer curves and the heat transfer coefficient(HTC) curves. It was found that the HTC still increases when the boiling heat transfer closes the critical heat flux(CHF). To better evaluate the boiling heat transfer efficiency, the concept of heat flux growth rate per unit superheat is introduced. The dynamic behaviors of single and multiple bubbles were also recorded to study the mechanism of the boiling heat transfer. The bubble behavior characteristics show good consistent with the proposed heat flux growth rate. By comparing the heat transfer curves and the bubble dynamic behavior, the following characters of boiling heat exchange can be found: At low heat flux, the heat exchange is dominated by the bubble coverage on the surface, and the hydrophobic surface has better boiling heat transfer efficiency than the hydrophilic surface. As the heat flux increases, the vapor channel connecting a big bubble and the wall surface plays an important role in enhancing the heat transfer. The polymerization of bubbles on the hydrophobic surface forms bubble films and breaks the vapor channel, leading to a significantly smaller HTC and a lower CHF than that of the hydrophilic surface. The HTC of hydrophilic surface in this work can reach up to 54.85 kW/(m^(2)·K), which is 2.3 times the hydrophobic surface.

关键词： boiling heat transfer boiling curve bubble dynamic

Numerical study on two-phase boiling heat transfer performance of interrupted microchannel heat sinks

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Science China(Technological Sciences) 2022年第3期65卷 679-692页

作者： ZHOU JianHong CHEN XueMei LI Qiang MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China

The conventional straight microchannel heat sinks have been reported to inadequately remove the increasing power density of *** recent years,an effective heat transfer enhancement method,flow disruptions have attracted the attention of researchers,where interrupted structures are arranged in the microchannel to enhance flow mixing and heat ***,previous numerical studies of interrupted microchannel heat sinks(I MCHS)mainly focus on single-phase flow condition,and the characteristics of the boiling heat transfer of I MCHS in two-phase flow condition have been rarely ***,the flow and heat transfer characteristics of two I MCHS based on rectangular microchannel heat sink(R MCHS)are investigated by modeling both single-phase and two-phase flow *** two interrupts consist of a combination of cavities and ribs,namely elliptical cavities and elliptical side ribs(EC-ESR),and elliptical cavities and elliptical central ribs(EC-ECR).The results show that for single-phase flow condition,the maximum Nusselt number is increased by 187%in the EC-ESR design and150%in the EC-ECR design compared with the R *** subcooled boiling(i.e.,two-phase flow)condition,the EC-ECR design is a promising structure to enhance boiling heat transfer with 6.7 K reduction of average wall temperature and 29%increment of local heat transfer coefficient when compared with those of R ***,the local heat transfer coefficient in the EC-ESR design is decreased by 22%compared with the R MCHS due to the formation of a rare flow pattern(i.e.,inverted annular flow with vapor film separation)in the *** flow pattern can induce departure from nucleate boiling(DNB),thereby deteriorating the heat transfer on the channel walls.

关键词： microchannel heat sink cavities and ribs thermal performance flow pattern boiling heat transfer flow disruptions

boiling heat transfer Enhancement in a Vertical Annulus by Introduction of Air in Liquid Flow

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Chinese Journal of Chemical Engineering 2004年第5期12卷 633-638页

作者：王军苗君刘芸沈自求 School of Chemical Engineering Dalian University of Technology Dalian 116012 China

In this paper, boiling heat transfer in a vertical annulus with inner side heated with and without air introduction is experimentally studied. Results show that boiling heat transfer is significantly enhanced by the introduction of air. When air is introduced into the liquid with a temperature below boiling point, the enhancement of heat transfer is also detected. It is concluded from the study that the heat transfer enhanced by introduction of inert gas is due to the liquid vaporization at the gas-liquid interface near the wall, which removes a large amount of latent heat and lowers the interfacial temperature considerably. Thus the gas-liquid interface acts as a 'heat sink'and the heat transfer is augmented significantly.

关键词： boiling heat transfer vertical annulus tube air introduction interfacialvaporization heat sink

Experimental and Numerical Analysis of the Influence ofMicrochannel Size and Structure on boiling heat transfer

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Computer Modeling in Engineering & Sciences 2023年第9期136卷 3061-3082页

作者： Ningbo Guo Xianming Gao Duanling Li Jixing Zhang Penghui Yin Mengyi Hua School of Mechanical and Electrical Engineering Shaanxi University of Science and TechnologyXi’an710021China

Computational fluid dynamics was used and a numerical simulation analysis of boiling heat transfer in microchannels with three depths and three cross-sectional profiles was *** heat transfer coefficient and bubble generation process of three microchannel structures with a width of 80μm and a depth of 40,60,and 80μm were compared during the boiling process,and the factors influencing bubble generation were studied.A visual test bench was built,and test substrates of different sizes were prepared using a micro-nano *** the test,the behavior characteristics of the bubbles on the boiling surface and the temperature change of the heated wall were collected with a high-speed camera and a temperature *** was found that the microchannel with a depth of 80μm had the largest heat transfer coefficient and shortest bubble growth period,the rectangular channel had a larger peak heat transfer coefficient and a lower frequency of bubble occurrence,while the V-shaped channel had the shortest growth period,i.e.,the highest frequency of bubble occurrence,but its heat transfer coefficient was smaller than that of the rectangular channel.

关键词： Microchannel boiling heat transfer bubble numerical simulation visual experiment

Neural Network Model for boiling heat transfer of R22 and Its Alternative Refrigerants inside Horizontal Smooth Tubes

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Journal of Shanghai Jiaotong university(Science) 2005年第1期10卷 76-79页

作者：王微涓张春路 Inst.of Refrigeration and Cryogenics Shanghai Jiaotong Univ.Shanghai 200030 China

Accurate prediction of refrigerant boiling heat transfer coefficients is important for the design of evaporators. The generalized correlations have different forms, and could not provide satisfactory results for R22 and its alternative refrigerants R134a, R407C and R410A. This study proposes to use artificial neural network (ANNs) as a generalized correlation model, selects the input parameters of ANNs on the basis of the dimensionless parameter groups of existing correlations, and correlates the in-tube boiling heat transfer coefficients of the above four refrigerants. The results show that the ANNs model with the input and output based on the Liu-Winterton correlation has the best result. The root-mean-square deviations in training and test are 15.5% and 20.2% respectively, and approximately 85% of the deviations are within ±20%, which is much better than that of the existing generalized correlations.

关键词： refrigerant smooth tube boiling heat transfer correlation neural network

boiling heat transfer in an Acoustic Cavitation Field

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Chinese Journal of Chemical Engineering 2002年第5期10卷 625-629页

作者：周定伟刘登瀛 Institute of Engineering Thermophysics Chinese Academy of Sciences 北京 100800 Institute of Engineering Thermophysics Chinese Academy of Sciences 北京 100080

An experimental study has been carried out investigatesystematically the effects of acoustic cavi- tation parameters andfluid subcooling on boiling of acetone around a horizontal circulartube. The experimental results show that acoustic cavitation enhancedremarkably the boiling heat transfer and decreased the incipientboiling superheat and that cavitation bubbles effect on boiling heattransfer reduced with cavitation distance. For boiling curves in aform of h-q', elevated cavitation distance shift nucleate boilingcurves to the right of the cor- responding ordinary pool boilingcurve. The associated mechanism of heat transfer enhancement isanalyzed with the consideration of cavitation bubble influence onvapor embryo.

关键词： acoustic cavitation boiling heat transfer hysteresis

Critical heat Flux of boiling heat transfer in aModerate Narrow Space

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Journal of Thermal Science 1998年第2期7卷 104-110页

作者： Yao－HuaZhan TakashiMasuoka 等 InstituteofIndustrialScience UniversityofTokyoTokyo106－8558Japan KyushuInstituteofTechnology Kitaky

boiling heat transfer process is analyzed in a moderate narrow space consisted of two horizontal *** main difference between this process and the conventional unconfined pool boilillg is the liquidsupply mechanism which is absolutely prevented by the growth of coalescence bubble along with theheated surface in the narrow space. As a result, the macrolayer becomes thinner due to the evaportion of the individual bubbles within the macrolayer during the period of bubble coalescence, with orwithout dryout that depends on both the gap size of narrow space and the size of heated surface. Fora specified size of the heated surface, the initial thickness of the liquid layer has a critical value whichapproaches a constant while the space height is larger than a critical value. The individual bubblebehaviors and tlie heat transfer can be considered as the same as that in the unconfined pool boiling, ifthe space gap is large. However, the individual bubbles do not generate in the last period of the bubblecoalescence and a lower maximum heat fiux will be resulted if the space gap is reduced. In such a case,the macrolayer is dryout.

关键词： boiling heat transfer critical heat flux coalescence bubble

boiling heat transfer with acoustic cavitation

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Progress in Natural Science:Materials International 2002年第6期 70-73页

作者： ZHOU Dingwei and LIU Dengying(Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080, China)

The effects of acoustic cavitation and nanometer granule on boiling heat transfer of horizontal circular copper tube are investigated experimentally and theoretically using acetone as the working fluid according to the boiling procedure. The results show that heat transfer can be enhanced or weakened by generation of the cavitation bubble or addition of the nanometer granules, respectively. The mechanisms of the effects are analyzed.

关键词： acoustic cavitation boiling heat transfer nanometer grannie.